Electric heating unit



June 29 1926.

A. J. MOTTLAU ELECTRIC HEATING UNIT Filed July 19, 1924 INVENTOR AuqusfJ/Vofi/au A'i'TORNEY- wlmssszsi 6 .-%W 177%; I W

Patented June 29, 1926.

UNITED STATES PATENT OFFICE.

' AUGUST J. MOTTLAU, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TC WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRIC HEATING UNIT.

Application filed July 19, 1924. Serial No. 726,905.

My invention relates to electrical heating units and particularly to resistor supporting means therefor.

The object of my invention is to provide a relatively simple, light-weight, and easily installed heating unit'for an electrically heated device.

In practicing my invention, I provide a plate of metal that has a plurality of laterally extending lugs having bent-over ,outer ends. Refractory resistor-supporting members of electric-insulating material are interlocked with the laterally extending lugs and with the plate, and are each provided with a laterally extending groove in an angular face thereoi through which a resistor member extends.

In the single sheet of drawings,

Figure 1 is a top plan view of a portion of a heating unit embodying my invention.

Fig. 2 is a view, partially in side elevation and partially in section, of a device embodying my invention,

. Fig. 3 is a bottom plan view of a refractory resistor supporting member, and

Fig.4 isa a mentary view, in lateral section, of a mo ified form of device embodying my invention.

A heating unit 11 comprises a plate 12 tha is preferably made of relatively thin sheet metal of any suitable or desired contour and dimensions. A plurality of lugs 13, integral with the plate 12, are punched therefrom and are bent to extend laterally from the surface of the plate and are each provided with a small bent-over end portion 14, as is more particularly illustrated in Fig. 2 of the drawings. Openings 15 are of course, provided where the lugs 13 have been punched out from the bottom of the plate. The lugs 13 may be located in any suitable or desired spacmg oralinemcnt relatively to each other, and the top plan view of Fig. 1 of the drawings is more of a schematic than an actual represenetation, of a heating unit, as the lugs 13 ma be located in a spiral path on a substantial y circular plate,-

or in any other desired arrangement, relatively to each other.

A. refractory member 16, of a suitable electric-insulating material, operatively en- ;gages the lug 13, it being provided with a.

' central groove 17 in one of its faces within which the laterally-extending straight portion of the lug 13 may be located, and projecting side portions 18 for preventing movement of the member 16, relatively to the cooperating ]ug 13. The bottom surface of the member 16 is provided with a central projecting integral portion 19 that interfits with the opening 15. The projecting portion 19 prevents lateral motion of the member 16 and its action is to assist the interfitting portions of the lug 13 and the side surface of the member 16. The portion 14 of the lug 13 fits over the outer surface of the member 16 and tends to prevent movementof the member 16 laterally away from the surface of the plate 12.

The members 16 are severally provided with an angularly disposed surface opposite to the face having the groove 17 and a laterally extending gl'OOVQ 21 is provided therein to receive a resistor member 22 that is preferably of a helically wound resistor wire of suitable dimensions. The resistor member 22 extends through the grooves or slots 21 and between the respective members 16.

It may be noted that the lugs 13 are so arranged and provided with the bent -over portions 14 that the open grooves 21 receive the resistor member 22 in such manner that the substantially resilient resistor member 22 callyzwound resistor member tends to hold the refractory resistor member in its proper operative engagemen substantially as illustrated in the drawings. Hence, it is only necessary to initially lay out the desired configuration of the resistor member and then to provide the bent-over portions 14 of the lugs 13 to co-operate therewith in view of the above-mentioned requirement.

In Fig. 4 of the drawings,I have illustrated a slightly modified design of integral lug, in whichlugs 23 do not extend at substantially right angles to the face or surface of the plate 12' but extend'at anacute angle thereto The refractory resistor-suporting members 24 co-operatmg with the nt-over lugs 23 may be of substantlally the sameconstruction as hereinbefore described for the members 16,. or their form ma be slightly eh I d, ,as'is more particular y illustrated in Fig. 4 so that the grooves 25 are located in a substantially laterally-exas was hereinbefore described for the construction illustrated in Figs. 1 and 2 of the drawings.

The members 24 are provided with a slot or groove within which the main portion of the lug 23 may be located, as was hereinbefore described for themembers 16, and they may also be provided with extensions 26 that fit into the openings left by the punched-out lugs 23.

1 preferably locate the heating element 11 in such position that the plate 12 does not carry any cooking utensils placed thereon, but so that a cooking utensil (not shown) is supported by the bent-over portions 14 and substantially all of the heat generated by the resistor member 22 is transmitted by direct radiation to the bottom surface of the cooking utensil.

Any suitable or desired means for strengthening the plate 12 to permit of its supporting a relatively heavy cooking utensil ma be provided, as is usual in the art.

Whi e I have illustrated a sheet metal plate comprising integral and punched out-lugs,

I do not desire to be limited thereto, as the.

plate may be cast and the lugs will then be cast integral therewith and the openings 15 will be provided by suitable core means in a manner well known in the art.

, The device embodying my invention thus provides a relatively simple and light weight heating unit for an electric heatlng device that is easily and quickly manufactured, in

which the heat storage capacity has a relatively low value, and in which the heating element assists in maintaining the refrac-. tory resistor supporting members in their proper positions interlocked with the sup porting plate.

While l have shown and described a particular form of an invention, chan es may be made therein without departing rom the spirit and scope thereof, and I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art.

it claim as my invention:

1. lln an electric heating unit, the combimacaw nation with a metal plate having a plurality of spaced, integral laterally extendlng lugs, and a plurality of openings adjacent to said lugs, of a plurality of refractory resistorsupporting members interfitting with said lugs and said openings, each refractory member having an open groove therein, and a 3. In an electric heating unit, the combi-- nation with a metal plate having a plurality of openings therethrough and comprising a plurality of bent-over lugs extending therefrom to constitute a utensil-supporting means, of a plurality of refractory members interfitting with said plate and said lugs, and a resistor member extending through said refractory members and therebetween and maintained thereby between said late and the outer ends of said bentover ugs.

4. In an electric heating unit, the combination with a metal plate having a plurality of punched-out bent-over lugs, of a plurality of refractory members, of electric-insulating material, each having a groove in one face thereof to interfit with one of said lugs and a projection on another face to interfit with also a laterally-extending groove in another face, and a resistor member extending through said groove and between said refractory members and effective to maintain said refractory members in their proper operative positions.

In. testimony whereof, I have hereunto subscribed my name this 10th day of July anensr J. MOTTLAU. 

